Pneumatic well drill



March 10, 1936. R, E. KITCHING PNEUMATIC WELL DRILL Filed Aug. 27, 1934In an Patented Mar. 10, 1936 UNI-TE s'rArs r at This invention relatesto pneumatic tools and particularly pertains to tools of the type inwhich fluid pressure actuated mechanism is operated while submerged inliquid; the invention more specifically appertaining to pneumaticallyoperated well drills in which a liquid or mud is circulated through thewell bore during drilling operations.

An object of the invention is to provide a well drill of the abovecharacter embodying a shank fitted with a compressed air operatedcutting tool and which is designed to be carried on a revoluble tubularstem through which circulating liquid or mud is delivered to the wellbore, in which means are provided whereby the liquid or mud may beconveyed from the stem and discharged adjacent the cutting tool on theshank apart from the air operated mechanism in' the shank; a particularobject being to provide a construction whereby the liquid or mud may beconveyed exteriorly of the drill shank substantially throughout thelength thereof, so as to obviate the necessity of forming the shank withbores or ducts for conveying the liquid or mud,

thereby simplifying the construction of the drill and effecting a greateconomy in its manufacture.

Another object is to provide a drill embodying the above features inwhich the liquid conveying element is so formed as to serve as areinforcement of the drill shank, and also act as a shield to protectthe drill shank during operation of the drill.

Another object isto provide construction where-- by a free flow of theliquid or mud from the stem along the shank to the cutting tool will beinsured, and whereby clogging of the liquid passages will be practicallyobviated.

Another object is to provide a pneumatic drill with a water jacketwhereby liquid may be caused to flow over the external surface of thedrill shank in such manner as to effect a cooling action thereon.

A further object is to provide a simple and effective method offorming adrill shank with a hereinafter described and claimed, and illustrated bywayof example, in the accompanying drawing; it being understood, howeverthat the invention as herein set forth is not to be limited to the exactconstruction shown, as the construetion may be subject to variouschanges and modifications to meet varying conditions and accordingly thefollowing specification of the invention is to be considered in itsbroadest sense and to 5 include equivalents coming within the meaning ofthe appended claims.

In the drawing:

Fig. l is a View of the drill as seen in side elevation:

Fig. 2 is a detail in cross section taken on line 2-2 of Fig. 1:

Fig. 3 is a view of the drill in longitudinal section with parts shownin elevation as seen on the line 3-3 of Fig. 2: 15

Fig. 4 is a detail in longitudinal section taken on line 4-4 of Fig. 2:

Fig. 5 is a detail in cross section taken on line 5'5 of Fig. 3:

Fig. 6 is a detail in cross section taken on line 6Ii of Fig. 3:

Fig. 7 is a detail in section taken on the line 7-1 of Fig. 3: I

Fig. 8 is a. view in section as seen on the line 8-B of Fig. 3:

Fig. 9 is a section and end view of the drill as seen from the lower endthereof on the line 99 of Fig. 3.

Referring to the drawing more specifically, A indicates generally theshank of a pneumatic well drill which is here shown as comprising aseries of interconnected sections including an upper end section it], alower end section I I, and united intermediate sections I2, I3, It, andI5 connecting the end sections IE] and H. The upper end section II) isconnected to the intermediate section I2 by a screw-threaded joint It,the sections I2 and I3, I3 and I4, I4 and I5, I5 and II areinterconnected by telescoped joints, as shown in Fig. 3.

The lower end section II carries a cutting tool or bit I1 which isdemountablyattached to a stem I8 reciprocally supported in the endsection II and extending through a seal I9 carried on the latter, theupper end portion of the stem I8 being provided with a collar 20 locatedin a recess 2| formed in theend section II against which and the bottomof the recess 2| is interposed a spring 22 which acts to normallymaintain the cutting tool or bit H in a retracted position. The upperend of the stem I8 is squared as indicated at 23 and passes through aguideway 24 formed in the intermediate section I5 whereby the stem I8 isheld against rotation on its axis.

Mounted in' a bore 25 formed in the intermediate section II .is areciprocal hammer 28 arranged to impact on the upper end of the stem l8when in operation. The hammer 26 is here shown as carried on a pistonrod 21, the upper end portion of which passes through a packing gland 28and is connected to a piston 29 arranged in a cylinder 30 carried in theintermediate shank section i3. The upper end of the cylinder 30 isformed in the section |2 of the shank in which is mounted a conventionalvalve 3| for controlling the intake and exhaust of air under pressure toand from the cylinder 38 on opposite sides of the piston 29 as is commonin pneumatic tool operating mechanism.

The section l2 and the walls of the cylinder 30 are formed with theusual ports and passages for eifecting the intake and exhaust of airunder pressure not necessary to be here shown but which includes anintake passage 32 leading from the upper end portion oi the section l2centrally thereof and communicating through a port 33 with the valve 3|,and also including an exhaust passage 34 leading from a chamber 35 inthe upper end of the section l2 and communicating with the valve 3|.

An intake pipe 36 leading from any suitable source of fluid pressuresupply such as a reservoir of compressed air is connected to the intakepassage 32 and connecting with the chamber 35 is an exhaust pipe 31which encircles the intake pipe 36 and leads to any suitable point ofdischarge.

The upper end portion of the end section i0 is .adapted to be connectedto a tubular stem 38 on which the drill is carried and through which theintake and exhaust pipes 36 and 31 extend.

The tubular stem 38 serves as a means for effecting rotation of thedrill and for this purpose is revolved in any suitable manner as iscommon in oil-well drilling operations. The stem 38 also serves as ameans for conveying a circulating liquid or mud into the well bore whichis eifected by connecting the upper end oi the stem 38 to a source 0!liquid or mud supply under pressure in the usual manner.

An important feature of the present invention resides in the provisionof a means for conveying liquid or mud from the stem 38 downwardly alongthe drill shank A and effecting its discharge adiacent the lower end ofthe latter and contiguous the cutting tool or bit IT. This means is hereshown as embodying a tubular metallic shell 40 which encircles orencompasses the shank A and extends substantially throughout the lengthof the latter. The shell 46 is spaced from the outer periphery of theshank A to provide a space 4| constituting a passage through whichliquid or mud may flow from the upper to the lower end portion of thedrill shank exteriorly of the latter. The shell 40 may be ailixedrelative to the shank A in any desired manner but is here shown assecured thereto at its ends through the medium of collars 42 and 43formed on the upper and lower end sections l0 and II respectively of theshank, which collars have telescoped engagement with the ends of theshell 48 and hold the latter in spaced concentric relation to the shankA.

As a means for affording a communication between the interior of thestem 38 and the space 4| interiorly of the shell 40 the end section illof the shank is formed with a series of passages 5| which leaddownwardly from the upper end of the shank and open to the sides of thelatter into the space 4| as particularly shown in Fig. 3.

As a means for permitting discharge of the liquid or mud from thepassage 4| the section II is formed with a series of passages 52; thesepassages being here shown as fitted with nozzles 53 inclineddownwardlyand inwardly towards opposite sides of the cutting tool l1whereby on discharge of liquid or mud through the section I a series ofjets thereof will be directed against the cutting tool in such fashionas to effect a cleaning action thereon during operation.

By thus encompassing the shank A with the shell 40 ample space isprovided for the passage of the usual circulating liquid or mud withoutthe necessity of forming the shank proper with ducts or bores for thispurpose. Furthermore, the shell 40 serves as a reenforcement tostrengthen the shank and also affords a protection thereto.

As a means collectively holding the shell 40 and the several shanksections together in a fashion which will permit of their readyassemblage and disassemblage, a series of tie rods 54 are employed,which rods extend longitudinally of the space 4| and have their endportions passed through the end sections l6 and II and fitted with nuts55 screwed thereon. The intermediate shank sections |2, |3, H, and I5are formed with radial webs 56 having longitudinal channels 51 in whichthe tie rods 54 seat as shown in Fig. 7 which webs serve as guides tofacilitate assemblage of the several shank sections in their properrelative positions as also serve in co-operation with the tie rods toform partitions or walls separating the space 4| into a series ofpassages as shown in Figs. 6 and 7 whereby accumulation and packing ofsolids in the space 4| during operation is prevented.

As a means for protecting the seal I9, nozzles 53 and nuts 54 againstinjury, a guard cap 58 is secured to the lower section by a threadedring 59 and which cap is formed with openings 60 disposed opposite thedischarge ends of the nozzles 53. The cap is preferably formed in halvesas shown in Fig. 9 to permit it being put in place and removed withoutnecessitating detachment of the bit H.

In the operation of the invention the drill shank A with its attachedshell 46 and the cutting tool I! thereon, is secured to the tubulardrill stem 38 with the air intake pipe 36 and the air exhaust pipe 31connected in place and extending through the drill, stem. to theirrespective points of termination. The drill stem is lowered into thewell and rotated in the usual manner common in rotary well-drillingoperations and during rotation thereof the cutting tool I1 isreciprocated by the action of compressed air on the piston 29 and hammer26 through the medium of the air-controlled mechanism as is common inpneumatic tool operations. A suitable liquid or mud is forced into thewell bore under pressure through the tubular stem 38 by means oi. theusual pump; the liquid or mud being delivered from the stem 38 throughthe passages 5| into the space or passage 4| around the drill shank andthence delivered from the lower end oi the shank through the passages 52and nozzles 53 into the well bore from whence it flows and iscirculatedin the usual manner. The incoming liquid or mud in passingdown the passage 4| in contact with substantially the entire outerperiphery of the drill shank will act to absorb and carry away a portionof the heat generated by the operation of the hammer and the compressedair operated mechanism thus eifecting a cooling action on the drilltherethrough, nozzles arranged to direct liquid I claim: 1. In apneumatic well drill, a shank having end sections, a tubular liquidconveying stem carrying said shank, a shell encompassing said shank andhaving telescoped engagement with the end sections thereof, there beinga space between said shell and shank opening adjacent one end of saidshank, passages in one end portion of said shank affording communicationbetween theinteriors of said stem and shell, and tie rods in said spaceinterconnecting said end sections and detachably holding said shell inplace. 2. In a pneumatic well drill, a shank havin end sections andembodying a plurality of telescopically interconnected intermediatesections, a shell encompassing said shank and telescopically connectedat its ends to the end sections of said shank, and tie rodsinterconnecting the end sections of said shank.

3. In a pneumatic well drill, a shank having end sections embodying aplurality of intermediate sections telescoped together, a shellencircling said shank, and connections leading between said shell andshank connecting the end sections of said shank for securing saidsections and shell against disengagement.

4. In a pneumatic well drill, a shank having end sections and embodyinga plurality of interconnected intermediate sections, webs on saidintermediate section, a shell encircling said shank, a telescopedconnection between said shell and each end section of said shank, andtie rods connecting the end sections of the shank tor securing saidsections and shell against disengagement, said tie rods engaging saidwebs.

5. In a pneumatic well drill, a shank, a cutting tool carried on one endof said shank, a collar encircling saidshank adjacent the end thereofcarrying said tool having liquid discharge passages inwardly from saidpassages toward the opposite sides of said tool, a shell encircling saidshank connected at one end to said collar, there being a space betweensaidshell and shank extending substantially throughout the length of thelatter communicating with said passages, and means for directing astream of liquid into the upper portion of said space.

6. In a pneumatic well drill of the class described, a shank, a cuttingtool carried on the lower end 01.- said shank, a collar on the upper endportion of said shank, a shell encircling said shank forming a liquidconduit extending substantially throughout the length of said shankexteriorly thereof, said shell encircling said collar and connectedthereto, a collar on the lower end portion 01' said shank encircled bythe lower end portion of said shell and to which said shell isconnected, said last named collar being formed with inclined passages,and nozzles leading from said passages, opening toward the sides of saidcutting tool. A

'1. In a pneumatic well drill oi the class described, a shank having endsections and embodying a plurality of telescopically interconnectedintermediate sections, webs extending longitudinally of saidintermediate sections, a shell encircling said shank in spaced relationthereto and telescopically engaging said end sections and abuttingendwise thereagainst, and tie-rods seating on said webs and extendinglongitudinally thereof for collectively securing said shank sections andshell together, said tie rods abutting the inner periphery of said shelland co-acting with said webs to divide the space between said shank andshell into a plurality of longitudinally extending passages.

ROY E. KITCHING.

